// SPDX-License-Identifier: MIT
/**
 * Copyright (c) 2019-2024 Hailo Technologies Ltd. All rights reserved.
 **/

#include "hailo_resource.h"

#include "utils.h"

#include <linux/io.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/kernel.h>

#define ALIGN_TO_32_BIT(addr) ((addr) & (~((uintptr_t)0x3)))

u8 hailo_resource_read8(struct hailo_resource *resource, size_t offset)
{
    u32 val = ioread32((u8*)ALIGN_TO_32_BIT(resource->address + offset));
    u64 offset_in_bits = BITS_IN_BYTE * ((resource->address + offset) - ALIGN_TO_32_BIT(resource->address + offset));
    return (u8)READ_BITS_AT_OFFSET(BYTE_SIZE * BITS_IN_BYTE, offset_in_bits, val);
}

u16 hailo_resource_read16(struct hailo_resource *resource, size_t offset)
{
    u32 val = ioread32((u8*)ALIGN_TO_32_BIT(resource->address + offset));
    u64 offset_in_bits = BITS_IN_BYTE * ((resource->address + offset) - ALIGN_TO_32_BIT(resource->address + offset));
    return (u16)READ_BITS_AT_OFFSET(WORD_SIZE * BITS_IN_BYTE, offset_in_bits, val);
}

u32 hailo_resource_read32(struct hailo_resource *resource, size_t offset)
{
    return ioread32((u8*)resource->address + offset);
}

void hailo_resource_write8(struct hailo_resource *resource, size_t offset, u8 value)
{
    u32 initial_val = ioread32((u8*)ALIGN_TO_32_BIT(resource->address + offset));
    u64 offset_in_bits = BITS_IN_BYTE * ((resource->address + offset) - ALIGN_TO_32_BIT(resource->address + offset));
    iowrite32(WRITE_BITS_AT_OFFSET(BYTE_SIZE * BITS_IN_BYTE, offset_in_bits, initial_val, value),
        (u8*)ALIGN_TO_32_BIT(resource->address + offset));
}

void hailo_resource_write16(struct hailo_resource *resource, size_t offset, u16 value)
{
    u32 initial_val = ioread32((u8*)ALIGN_TO_32_BIT(resource->address + offset));
    u64 offset_in_bits = BITS_IN_BYTE * ((resource->address + offset) - ALIGN_TO_32_BIT(resource->address + offset));
    iowrite32(WRITE_BITS_AT_OFFSET(WORD_SIZE * BITS_IN_BYTE, offset_in_bits, initial_val, value),
        (u8*)ALIGN_TO_32_BIT(resource->address + offset));
}

void hailo_resource_write32(struct hailo_resource *resource, size_t offset, u32 value)
{
    iowrite32(value, (u8*)resource->address + offset);
}

void hailo_resource_read_buffer(struct hailo_resource *resource, size_t offset, size_t count, void *to)
{
    // Copied and modified from linux aarch64 (using ioread32 instead of readq that does not work all the time)
    uintptr_t to_ptr = (uintptr_t)to;
    while ((count > 0) && (!IS_ALIGNED(to_ptr, 4) || !IS_ALIGNED((uintptr_t)resource->address + offset, 4))) {
        *(u8*)to_ptr = hailo_resource_read8(resource, offset);
        to_ptr++;
        offset++;
        count--;
    }

    while (count >= 4) {
        *(u32*)to_ptr = hailo_resource_read32(resource, offset);
        to_ptr += 4;
        offset += 4;
        count -= 4;
    }

    while (count > 0) {
        *(u8*)to_ptr = hailo_resource_read8(resource, offset);
        to_ptr++;
        offset++;
        count--;
    }
}

int hailo_resource_write_buffer(struct hailo_resource *resource, size_t offset, size_t count, const void *from)
{
    // read the bytes after writing them for flushing the data. This function also checks if the pcie link
    // is broken.
    uintptr_t from_ptr = (uintptr_t)from;
    while (count && (!IS_ALIGNED(resource->address + offset, 4) || !IS_ALIGNED(from_ptr, 4))) {
        hailo_resource_write8(resource, offset, *(u8*)from_ptr);
        if (hailo_resource_read8(resource, offset) != *(u8*)from_ptr) {
            return -EIO;
        }
        from_ptr++;
        offset++;
        count--;
    }

    while (count >= 4) {
        hailo_resource_write32(resource, offset, *(u32*)from_ptr);
        if (hailo_resource_read32(resource, offset) != *(u32*)from_ptr) {
            return -EIO;
        }
        from_ptr += 4;
        offset += 4;
        count -= 4;
    }

    while (count) {
        hailo_resource_write8(resource, offset, *(u8*)from_ptr);
         if (hailo_resource_read8(resource, offset) != *(u8*)from_ptr) {
            return -EIO;
        }
        from_ptr++;
        offset++;
        count--;
    }

    return 0;
}

int hailo_resource_transfer(struct hailo_resource *resource, struct hailo_memory_transfer_params *transfer)
{
    // Check for transfer size (address is in resources address-space)
    if ((transfer->address + transfer->count) > (u64)resource->size) {
        return -EINVAL;
    }

    if (transfer->count > ARRAY_SIZE(transfer->buffer)) {
        return -EINVAL;
    }

    switch (transfer->transfer_direction) {
    case TRANSFER_READ:
        hailo_resource_read_buffer(resource, (u32)transfer->address, transfer->count, transfer->buffer);
        return 0;
    case TRANSFER_WRITE:
        return hailo_resource_write_buffer(resource, (u32)transfer->address, transfer->count, transfer->buffer);
    default:
        return -EINVAL;
    }
}